1. Field of the Invention
The invention relates to an electrical installation box for flush mounting in walls, in particular in hollow walls. The box has claws which are movable relative to the box and with which the box is secured in an opening formed in the wall. Each claw is attached at a pull strap, which is slidably guided along the axial direction of the box (perpendicularly to the wall surface) in a guide of the box. The pull strap is formed with which a serration and there is an associated counter toothing formed on the box.
It is well known that it is often difficult to rigidly attach electrical boxes (for switches, outlets, sockets, etc.), in an opening in a wall and, particularly, if it is a hollow wall, as it is often the case with sheetrock or wooden walls. Conventional boxes for such applications have metal claws that can each be tightened by means of a screw held in the box. The mounting time necessary therefor is substantial and the production costs for such boxes are relatively high.
2. Description of the Related Art
Electrical installation boxes of the above-mentioned kind have therefore been developed (for example German patent DE-A 2 137 299 and French patent FR-A 2 147 029) in which the box is attached in the wall opening by pulling pull straps in the axial direction of the box. When the pull strap is pulled out of the box, the teeth of the pull strap glide over the teeth of the counter toothing until the claws come to lie on the edge of the wall opening in which the box is to be mounted. When the desired end position is reached, then the counter toothing which has snapped into the toothing of the pull strap holds the pull strap in the adjusted position. The result is a secure anchoring of the box in the wall opening.
It has proved disadvantageous, however, that the tightening of the pull straps is cumbersome, as it can be done only with heavy pliers. Those prior art structures have therefore not been successful in practical application.